News-Medical -- A tiny heart catheter pump which supports the human heart in critical conditions while pumping has been developed at the Vienna University of Technology (TU Vienna). The pump may not be larger than five millimetres and no longer than 45 millimetres at a ratio of 1:1. It reaches the heart via a catheter and, placed in the heart valves, helps to pump blood from the heart. The pump drive which is operated pneumatically is particularly innovative. Construction scientists at the TU Vienna have produced a prototype of a ratio of 2:1 commissioned by heart surgeon and university professor Werner Mohl.